High Availability - From NetScaler to F5

Hmmm. Can you provide more detail on the IP setup please? I don't see how any setup (HA or otherwise) could accomodate two subnets for three ISPs with only three IPs. Surely the F5's don't need to actually have a 'leg' into each subnet? A bit of thought around NAT and/or routing should easily overcome the apparent wastage of addresses.